The present invention relates to the field of calibration of test and measurement instruments, and in particular to an apparatus and method for calibration of interleaved digitizer channel signal paths that allow acquisition of data at very high sample rates while maintaining a phase and magnitude match between the interleaved signal paths at all frequencies.
In a modern four-channel digital storage oscilloscope, the channels are currently individually calibrated through a very time consuming process during manufacturing. When two or more of these channels are then interleaved for higher sample rates, the new signal paths required for an input signal have to be matched for an accurate interleave. The paths must match in both phase and magnitude at all frequencies. However, current methods for calibrating these channels require calibrated step generators, resulting in difficulty for obtaining good match at high frequencies.
What is desired is a method of calibrating interleaved digitizer channels that is easy, does not require calibrated step generators, and can be performed either in the field or in the factory.